Method of reclaiming or improving gum exudates



Patented Dec. 23, 1930 UNITED STATES PATENT OFFICE CHARLES MARTELL, OF CICERO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OENEW YORK, N. Y., A CORPORATION OF NEW YORK METHOD OF RECLAIMING OR IMPROVING GUM EXUDATES No Drawing.

This invention relates to methods of re claiming or improving gum exudates, particularly methods of reclaiming or improving gutta percha, and has for its main object the provision of an improved method whereby inferior grades of such material may quickly and economically be fitted for commercial use.

The method consists primarily in mastieating an oxidized or inferior grade of coagulated gum exudate in the presence of rubber latex, the masticating process having the effect of reclaiming or improving the exudate, thewater in the latex functioning at the same time to wash the material and thereby remove extraneous or introduced impurities, such as earth and the like.

In order to explain more in detail the manner in which the process is carried out, specific reference will be made to its use for the purpose of reclaiming or improving inferior grades of gutta percha. This material is composed primarily of the hydrocarbon, gutta, with a comparatively large percentage of various forms of resins. When it has been exposed, however, to the air for any great length of time the gutta may oxidize, thereby producing an additional resin which further increases the resin content of the gutta pereha. Therefore, gutta percha may be of a great many different grades, each having a different percentage of resin. When working with such materials it is sometimes desirable to keep the proportion of pure gutta as near as possible to a standard and this is done, in some instances, by deresinating some of the gutta percha and then mixing it with other grades of gutta percha to produce the grade desired.

In addition to the resin content of gutta percha the material as marketed is frequently found to contain comparatively large amounts of foreign matter, such as leaves, twigs, earth and other similar substances, which make it necessary to wash the gum thoroughly before it is fit for use. A very great difficulty is experienced when dirty gutta percha, which at the same time has a high resin content, must be prepared for commercial use. 50 The resin has the effect of making the gutta Serial No. 28,511.

percha very adhesive and tacky and the resuit is that when an attempt is made to wash the material the dirt will not readily loosen and the material adheres to the masticating or washing apparatus in a way which makes the washing diiiicult.

This difiiculty may be overcome by following the process embodying the features of this invention, the gutta percha being placed in a suitable masticator with a quantity of rubber latex and then mastieated in the presence of the latex. The eifeet is that the gum in the latex is absorbed by or agglomerated with the gutta pereha, an intimate mixture of the two materials being obtained, and the Water present removes the foreign matter by its detergent action. When this method is employed a grade of gutta percha which is tacky and lacking in strength may be masticated in the manner described after which it presents the appearance of a normally good grade of gutta perchaand possesses all of the desirable characteristics of such a grade. Although the process is of particular advantage in the treatment of a material which is both resinous and contains foreign matter, which material would probably otherwise be unfit for use, a medium or inferior grade of clean gutta percha which is objectionable only from the standpoint of the resin content can be reclaimed and improved in such a way as to make it approach in its characteristics the better grades of gutta percha.

As a specific example quantity of gutta percha which had become so oxidized as apparently to be entirely worthless and from which the dirt could not be removed readily by other known methods because of the stick iness of the mass, was masticated in rubber latex in accordance with the present invention until it had absorbed about 12% of the gum in the rubber latex. The material was then found to be in an improved condition and appeared as a good grade of unoxidized gutta percha low in resin content. Equally goods results may be obtained in reclaiming or improving inferior or deteriorated grades of balata and rubber. Similar results were obtained in the reclaiming of balata, for instance, as in the reclaiming of gutta percha, that is, where the material was very badly oxidized an absorption of about 12% ot rubber imparted to it the characteristics of new unoxidized material.

Although good results obtained by the use of rubber latex as described, where it is )lQfOfzllJlO that the gum exudate have characteristics not producible by treatment with rubber latex, latex of the same origin as the gum exudate employed may be used. For instance, where gutta percha sought to be improved and 11 ust be bent pure tor some reason, it the added expense is w ranted, gutta latex may 1 he inanuer described. a

no used in t lvhatever class of latex is employed. however. it may he of a natural or :n :u'tiiirial origin and, it vulcanizatde, it may be vulcanized or unvulcanized as desired.

As noted above the rocess may be employed in the treatment of so-called dirty grades of materials or in the reclaimir only of such materials as a tree from extr. teens matter. The language of the appended claims is made to r r to the treatment of either class of material, the word in being used to refer to both conditions materials.

What is claimed is:

1. A method of reclaiming; an interior unvulcanized gum exudate, which consists in treating the gum exudate in the presence of a, relatively small quantity of latex until a quantity of the gum in the latex has been absorbed by the gum exudate.

A method of reclaiming; an interior unvulcaniZe-d gum exudate, which consists in treating; the gum exudate in the pix ence of a. relatively small quantity of latex of the same origin as the gum be treated until a quantity of: gum in the latex has been absorbed by the gum exudate.

The method oi reclaiming an inferior unvulcanized gum. exudate, which con. in treating the gum exudate in the pre ence of a relatyely small quantity of rubber latex. until a quantity of gum in the rubber latex has been absorbed by the gum exudate.

4. A method of reclaiming an interior grade of gutta 1 ercha, which consists in treating; the gutta percha in the presence of latex all until a quantity of the gum in the latex has been absorbed by the gutta )GlClltt.

5. A method ot reclaiming an inife r grade of gutta percha, which consists in treating the gutta percha in the presence of rubber latex until a quantity of the gum in the ruh her lat x has been absorbed by the gutta percha.

6. A method of reclaiming an inferior gum xudate, which consists in treating the gum exudate with a gum-containing material which acts as a detergent, and simultaneous ly therewith improves the quality of the gum exudate.

7. A method of reclaiminn interior utta O L, b

percha, which consists in treating me guru percha with a gum-containing material. "(\llifil a :ts as a detergent, and simultaneously the 'e qutta perch 1.

9. The method of reclaiming interior gutta percha, which consists in treating the gut-ta percha vith a gum-containin n'laterial which acts as a detergent and siniultaneeusly therewith increases the ;rum content ol the gutta percha.

10. A method of tr iating an uurulcanizml gum exuda e, which consists in inasticatiiur the gum exudate in the presence ot latex til a quantity oi" the gum in the later; an crates with the gum exudate.

11. A method at treating an n ivulrz" rum exudate, which consists in work" h gum exudate in the presence of latex, t -ei causing the liquid of the lat x to act a rwterg upon the gum exudate and causing; a. quantity of the gum in the latex to as fol crate with the gum exudate.

12. A method of treating an unx'u gum exudate other than rubber, which (onthe gum exudate in t i Y the date.

13. A method of treating an unvul 'anizcd gum exudate other than rubber, which consists in working the gum exudate in the presence of latex thereby causing the liquid of the latex to act as a detergent, upon the gum exulate and causing a quantity of the gum in the atex to a g; omerate with the gum exuda e.

A method of treating an unvulcanizcd gum exudate selected from the 'roup incl ud ingg; gutta percha, ialata, and n iures ot the two. wnich consists in working; the gum exudate in the presence of latex tin-mm causing: the liquid of the latex to act as a detergent upon the gum exudate and causinga quantity of the gum in the latex to agglomerate with the gum exudate.

In witness whereof, I he 'eunto subsn'zribe my name this 28th day of" April A. D., 192.7.

CHARLES MARTELL.

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